/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/python/gpu/gpu_py_shader.c
 *  \ingroup bpygpu
 *
 * - Use ``bpygpu_`` for local API.
 * - Use ``BPyGPU`` for public API.
 */

#include <Python.h>

#include "BLI_utildefines.h"

#include "GPU_shader.h"
#include "GPU_shader_interface.h"

#include "../generic/py_capi_utils.h"
#include "../generic/python_utildefines.h"
#include "../mathutils/mathutils.h"

#include "gpu_py_api.h"
#include "gpu_py_shader.h" /* own include */
#include "gpu_py_vertex_format.h"


 /* -------------------------------------------------------------------- */

 /** \name Enum Conversion.
 * \{ */

static int bpygpu_ParseBultinShaderEnum(PyObject *o, void *p)
{
	Py_ssize_t mode_id_len;
	const char *mode_id = _PyUnicode_AsStringAndSize(o, &mode_id_len);
	if (mode_id == NULL) {
		PyErr_Format(PyExc_ValueError,
		             "expected a string, got %s",
		             Py_TYPE(o)->tp_name);
		return 0;
	}
#define MATCH_ID(id) \
	if (mode_id_len == (Py_ssize_t)strlen(STRINGIFY(id))) { \
		if (STREQ(mode_id, STRINGIFY(id))) { \
			mode = GPU_SHADER_##id; \
			goto success; \
		} \
	} ((void)0)

	GPUBuiltinShader mode;
	MATCH_ID(2D_UNIFORM_COLOR);
	MATCH_ID(2D_FLAT_COLOR);
	MATCH_ID(2D_SMOOTH_COLOR);
	MATCH_ID(2D_IMAGE);
	MATCH_ID(3D_UNIFORM_COLOR);
	MATCH_ID(3D_FLAT_COLOR);
	MATCH_ID(3D_SMOOTH_COLOR);

#undef MATCH_ID
	PyErr_Format(PyExc_ValueError,
	             "unknown type literal: '%s'",
	             mode_id);
	return 0;

success:
	(*(GPUBuiltinShader *)p) = mode;
	return 1;
}

static int bpygpu_uniform_location_get(GPUShader *shader, const char *name, const char *error_prefix)
{
	int uniform = GPU_shader_get_uniform(shader, name);

	if (uniform == -1) {
		PyErr_Format(PyExc_ValueError, "%s: uniform %.32s %.32s not found", error_prefix, name);
	}

	return uniform;
}

/** \} */


/* -------------------------------------------------------------------- */

/** \name Shader Type
 * \{ */

static PyObject *bpygpu_shader_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
{
	BPYGPU_IS_INIT_OR_ERROR_OBJ;

	struct {
		const char *vertexcode;
		const char *fragcode;
		const char *geocode;
		const char *libcode;
		const char *defines;
	} params = {0};

	static const char *_keywords[] = {
	        "vertexcode", "fragcode", "geocode",
	        "libcode", "defines", NULL};

	static _PyArg_Parser _parser = {"ss|$sss:GPUShader.__new__", _keywords, 0};
	if (!_PyArg_ParseTupleAndKeywordsFast(
	        args, kwds, &_parser,
	        &params.vertexcode, &params.fragcode, &params.geocode,
	        &params.libcode, &params.defines))
	{
		return NULL;
	}

	GPUShader *shader = GPU_shader_create(
	        params.vertexcode,
	        params.fragcode,
	        params.geocode,
	        params.libcode,
	        params.defines,
	        NULL);

	if (shader == NULL) {
		PyErr_SetString(PyExc_Exception,
		                "Shader Compile Error, see console for more details");
		return NULL;
	}

	return BPyGPUShader_CreatePyObject(shader, false);
}

PyDoc_STRVAR(bpygpu_shader_bind_doc,
".. method:: bind()\n"
"\n"
"   Bind the shader object. Required to be able to change uniforms of this shader.\n"
);
static PyObject *bpygpu_shader_bind(BPyGPUShader *self)
{
	GPU_shader_bind(self->shader);
	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_uniform_from_name_doc,
".. method:: uniform_from_name(name)\n"
"\n"
"   Get uniform location by name.\n"
"\n"
"   :param name: Name of the uniform variable whose location is to be queried.\n"
"   :type name: `str`\n"
"   :return: Location of the uniform variable.\n"
"   :rtype: `int`\n"
);
static PyObject *bpygpu_shader_uniform_from_name(
        BPyGPUShader *self, PyObject *arg)
{
	const char *name = PyUnicode_AsUTF8(arg);
	if (name == NULL) {
		return NULL;
	}

	int uniform = bpygpu_uniform_location_get(
	        self->shader, name, "GPUShader.get_uniform");

	if (uniform == -1) {
		return NULL;
	}

	return PyLong_FromLong(uniform);
}

PyDoc_STRVAR(bpygpu_shader_uniform_block_from_name_doc,
".. method:: uniform_block_from_name(name)\n"
"\n"
"   Get uniform block location by name.\n"
"\n"
"   :param name: Name of the uniform block variable whose location is to be queried.\n"
"   :type name: `str`\n"
"   :return: The location of the uniform block variable.\n"
"   :rtype: `int`\n"
);
static PyObject *bpygpu_shader_uniform_block_from_name(
        BPyGPUShader *self, PyObject *arg)
{
	const char *name = PyUnicode_AsUTF8(arg);
	if (name == NULL) {
		return NULL;
	}

	int uniform = GPU_shader_get_uniform_block(self->shader, name);

	if (uniform == -1) {
		PyErr_Format(PyExc_ValueError,
		             "GPUShader.get_uniform_block: uniform %.32s not found", name);
		return NULL;
	}

	return PyLong_FromLong(uniform);
}

static bool bpygpu_shader_uniform_vector_imp(
        PyObject *args, int elem_size,
        int *r_location, int *r_length, int *r_count, Py_buffer *r_pybuffer)
{
	PyObject *buffer;

	*r_count = 1;
	if (!PyArg_ParseTuple(
	        args, "iOi|i:GPUShader.uniform_vector_*",
	        r_location, &buffer, r_length, r_count))
	{
		return false;
	}

	if (PyObject_GetBuffer(buffer, r_pybuffer, PyBUF_SIMPLE) == -1) {
		/* PyObject_GetBuffer raise a PyExc_BufferError */
		return false;
	}

	if (r_pybuffer->len != (*r_length * *r_count * elem_size)) {
		PyErr_SetString(
		        PyExc_BufferError,
		        "GPUShader.uniform_vector_*: buffer size does not match.");
		return false;
	}

	return true;
}

PyDoc_STRVAR(bpygpu_shader_uniform_vector_float_doc,
".. method:: uniform_vector_float(location, buffer, length, count)\n"
"\n"
"   Set the buffer to fill the uniform.\n"
"\n"
"   :param location: Location of the uniform variable to be modified.\n"
"   :type location: int\n"
"   :param buffer:  The data that should be set. Can support the buffer protocol.\n"
"   :type buffer: sequence of floats\n"
"   :param length: Size of the uniform data type:\n"
"\n"
"      - 1: float\n"
"      - 2: vec2 or float[2]\n"
"      - 3: vec3 or float[3]\n"
"      - 4: vec4 or float[4]\n"
"      - 9: mat3\n"
"      - 16: mat4\n"
"\n"
"   :type length: int\n"
"   :param count: Specifies the number of elements, vector or matrices that are to be modified.\n"
"   :type count: int\n"
);
static PyObject *bpygpu_shader_uniform_vector_float(
        BPyGPUShader *self, PyObject *args)
{
	int location, length, count;

	Py_buffer pybuffer;

	if (!bpygpu_shader_uniform_vector_imp(
	        args, sizeof(float),
	        &location, &length, &count, &pybuffer))
	{
		return NULL;
	}

	GPU_shader_uniform_vector(
	        self->shader, location, length,
	        count, pybuffer.buf);

	PyBuffer_Release(&pybuffer);

	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_uniform_vector_int_doc,
".. method:: uniform_vector_int(location, buffer, length, count)\n"
"\n"
"   See GPUShader.uniform_vector_float(...) description.\n"
);
static PyObject *bpygpu_shader_uniform_vector_int(
        BPyGPUShader *self, PyObject *args)
{
	int location, length, count;

	Py_buffer pybuffer;

	if (!bpygpu_shader_uniform_vector_imp(
	        args, sizeof(int),
	        &location, &length, &count, &pybuffer))
	{
		return NULL;
	}

	GPU_shader_uniform_vector_int(
	        self->shader, location, length,
	        count, pybuffer.buf);

	PyBuffer_Release(&pybuffer);

	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_uniform_bool_doc,
".. method:: uniform_bool(name, seq)\n"
"\n"
"   Specify the value of a uniform variable for the current program object.\n"
"\n"
"   :param name: Name of the uniform variable whose value is to be changed.\n"
"   :type name: str\n"
"   :param seq: Value that will be used to update the specified uniform variable.\n"
"   :type seq: sequence of bools\n"
);
static PyObject *bpygpu_shader_uniform_bool(
        BPyGPUShader *self, PyObject *args)
{
	const char *error_prefix = "GPUShader.uniform_bool";

	struct {
		const char *id;
		PyObject *seq;
	} params;

	if (!PyArg_ParseTuple(
	        args, "sO:GPUShader.uniform_bool",
	        &params.id, &params.seq))
	{
		return NULL;
	}

	int values[4];
	int length;
	int ret;
	{
		PyObject *seq_fast = PySequence_Fast(params.seq, error_prefix);
		if (seq_fast == NULL) {
			PyErr_Format(PyExc_TypeError,
			             "%s: expected a sequence, got %s",
			             error_prefix, Py_TYPE(params.seq)->tp_name);
			ret = -1;
		}
		else {
			length = PySequence_Fast_GET_SIZE(seq_fast);
			if (length == 0 || length > 4) {
				PyErr_Format(PyExc_TypeError,
				             "%s: invalid sequence length. expected 1..4, got %d",
				             error_prefix, length);
				ret = -1;
			}
			else {
				ret = PyC_AsArray_FAST(
				        values, seq_fast, length, &PyLong_Type,
				        false, error_prefix);
			}
			Py_DECREF(seq_fast);
		}
	}
	if (ret == -1) {
		return NULL;
	}

	const int location = bpygpu_uniform_location_get(
	        self->shader, params.id, error_prefix);

	if (location == -1) {
		return NULL;
	}

	GPU_shader_uniform_vector_int(self->shader, location, length, 1, values);

	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_uniform_float_doc,
".. method:: uniform_float(name, value)\n"
"\n"
"   Specify the value of a uniform variable for the current program object.\n"
"\n"
"   :param name: Name of the uniform variable whose value is to be changed.\n"
"   :type name: str\n"
"   :param value: Value that will be used to update the specified uniform variable.\n"
"   :type value: single number or sequence of numbers\n"
);
static PyObject *bpygpu_shader_uniform_float(
        BPyGPUShader *self, PyObject *args)
{
	const char *error_prefix = "GPUShader.uniform_float";

	struct {
		const char *id;
		PyObject *seq;
	} params;

	if (!PyArg_ParseTuple(
	        args, "sO:GPUShader.uniform_float",
	        &params.id, &params.seq))
	{
		return NULL;
	}

	float values[16];
	int length;

	if (PyFloat_Check(params.seq)) {
		values[0] = (float)PyFloat_AsDouble(params.seq);
		length = 1;
	}
	else if (PyLong_Check(params.seq)) {
		values[0] = (float)PyLong_AsDouble(params.seq);
		length = 1;
	}
	else if (MatrixObject_Check(params.seq)) {
		MatrixObject *mat = (MatrixObject *)params.seq;
		if (BaseMath_ReadCallback(mat) == -1) {
			return NULL;
		}
		if ((mat->num_row != mat->num_col) || !ELEM(mat->num_row, 3, 4)) {
			PyErr_SetString(PyExc_ValueError,
			                "Expected 3x3 or 4x4 matrix");
			return NULL;
		}
		length = mat->num_row * mat->num_col;
		memcpy(values, mat->matrix, sizeof(float) * length);
	}
	else {
		length = mathutils_array_parse(values, 2, 16, params.seq, "");
		if (length == -1) {
			return NULL;
		}
	}

	if (!ELEM(length, 1, 2, 3, 4, 9, 16)) {
		PyErr_SetString(PyExc_TypeError,
		                "Expected a single float or a sequence of floats of length 1..4, 9 or 16.");
		return NULL;
	}

	const int location = bpygpu_uniform_location_get(
	        self->shader, params.id, error_prefix);

	if (location == -1) {
		return NULL;
	}

	GPU_shader_uniform_vector(self->shader, location, length, 1, values);

	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_uniform_int_doc,
".. method:: uniform_int(name, seq)\n"
"\n"
"   Specify the value of a uniform variable for the current program object.\n"
"\n"
"   :param name: name of the uniform variable whose value is to be changed.\n"
"   :type name: str\n"
"   :param seq: Value that will be used to update the specified uniform variable.\n"
"   :type seq: sequence of numbers\n"
);
static PyObject *bpygpu_shader_uniform_int(
        BPyGPUShader *self, PyObject *args)
{
	const char *error_prefix = "GPUShader.uniform_int";

	struct {
		const char *id;
		PyObject *seq;
	} params;

	if (!PyArg_ParseTuple(
	        args, "sO:GPUShader.uniform_int",
	        &params.id, &params.seq))
	{
		return NULL;
	}

	int values[4];
	int length;
	int ret;

	if (PyLong_Check(params.seq)) {
		values[0] = PyC_Long_AsI32(params.seq);
		length = 1;
		ret = 0;
	}
	else {
		PyObject *seq_fast = PySequence_Fast(params.seq, error_prefix);
		if (seq_fast == NULL) {
			PyErr_Format(PyExc_TypeError,
			             "%s: expected a sequence, got %s",
			             error_prefix, Py_TYPE(params.seq)->tp_name);
			ret = -1;
		}
		else {
			length = PySequence_Fast_GET_SIZE(seq_fast);
			if (length == 0 || length > 4) {
				PyErr_Format(PyExc_TypeError,
				             "%s: invalid sequence length. expected 1..4, got %d",
				             error_prefix, length);
				ret = -1;
			}
			else {
				ret = PyC_AsArray_FAST(
				        values, seq_fast, length, &PyLong_Type,
				        false, error_prefix);
			}
			Py_DECREF(seq_fast);
		}
	}
	if (ret == -1) {
		return NULL;
	}

	const int location = bpygpu_uniform_location_get(
	        self->shader, params.id, error_prefix);

	if (location == -1) {
		return NULL;
	}

	GPU_shader_uniform_vector_int(self->shader, location, length, 1, values);

	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_attr_from_name_doc,
".. method:: attr_from_name(name)\n"
"\n"
"   Get attribute location by name.\n"
"\n"
"   :param name: The name of the attribute variable whose location is to be queried.\n"
"   :type name: str\n"
"   :return: The location of an attribute variable.\n"
"   :rtype: int\n"
);
static PyObject *bpygpu_shader_attr_from_name(
        BPyGPUShader *self, PyObject *arg)
{
	const char *name = PyUnicode_AsUTF8(arg);
	if (name == NULL) {
		return NULL;
	}

	int attr = GPU_shader_get_attribute(self->shader, name);

	if (attr == -1) {
		PyErr_Format(PyExc_ValueError,
		             "GPUShader.attr_from_name: attribute %.32s not found", name);
		return NULL;
	}

	return PyLong_FromLong(attr);
}

PyDoc_STRVAR(bpygpu_shader_calc_format_doc,
".. method:: calc_format()\n"
"\n"
"   Build a new format based on the attributes of the shader.\n"
"\n"
"   :return: vertex attribute format for the shader\n"
"   :rtype: GPUVertFormat\n"
);
static PyObject *bpygpu_shader_calc_format(BPyGPUShader *self, PyObject *UNUSED(arg))
{
	BPyGPUVertFormat *ret = (BPyGPUVertFormat *)BPyGPUVertFormat_CreatePyObject(NULL);
	GPU_vertformat_from_interface(&ret->fmt, GPU_shader_get_interface(self->shader));
	return (PyObject *)ret;
}

static struct PyMethodDef bpygpu_shader_methods[] = {
	{"bind", (PyCFunction)bpygpu_shader_bind,
	 METH_NOARGS, bpygpu_shader_bind_doc},
	{"uniform_from_name",
	 (PyCFunction)bpygpu_shader_uniform_from_name,
	 METH_O, bpygpu_shader_uniform_from_name_doc},
	{"uniform_block_from_name",
	 (PyCFunction)bpygpu_shader_uniform_block_from_name,
	 METH_O, bpygpu_shader_uniform_block_from_name_doc},
	{"uniform_vector_float",
	 (PyCFunction)bpygpu_shader_uniform_vector_float,
	 METH_VARARGS, bpygpu_shader_uniform_vector_float_doc},
	{"uniform_vector_int",
	 (PyCFunction)bpygpu_shader_uniform_vector_int,
	 METH_VARARGS, bpygpu_shader_uniform_vector_int_doc},
	{"uniform_bool",
	 (PyCFunction)bpygpu_shader_uniform_bool,
	 METH_VARARGS, bpygpu_shader_uniform_bool_doc},
	{"uniform_float",
	 (PyCFunction)bpygpu_shader_uniform_float,
	 METH_VARARGS, bpygpu_shader_uniform_float_doc},
	{"uniform_int",
	 (PyCFunction)bpygpu_shader_uniform_int,
	 METH_VARARGS, bpygpu_shader_uniform_int_doc},
	{"attr_from_name",
	 (PyCFunction)bpygpu_shader_attr_from_name,
	 METH_O, bpygpu_shader_attr_from_name_doc},
	{"format_calc",
	 (PyCFunction)bpygpu_shader_calc_format,
	 METH_NOARGS, bpygpu_shader_calc_format_doc},
	{NULL, NULL, 0, NULL}
};

PyDoc_STRVAR(bpygpu_shader_program_doc,
"The name of the program object for use by the OpenGL API (read-only).\n\n:type: int"
);
static PyObject *bpygpu_shader_program_get(BPyGPUShader *self, void *UNUSED(closure))
{
	return PyLong_FromLong(GPU_shader_get_program(self->shader));
}

static PyGetSetDef bpygpu_shader_getseters[] = {
	{(char *)"program",
	 (getter)bpygpu_shader_program_get, (setter)NULL,
	 bpygpu_shader_program_doc, NULL},
	{NULL, NULL, NULL, NULL, NULL} /* Sentinel */
};


static void bpygpu_shader_dealloc(BPyGPUShader *self)
{
	if (self->is_builtin == false) {
		GPU_shader_free(self->shader);
	}
	Py_TYPE(self)->tp_free((PyObject *)self);
}


PyDoc_STRVAR(bpygpu_shader_doc,
".. class:: GPUShader(vertexcode, fragcode, geocode=None, libcode=None, defines=None)\n"
"\n"
"   GPUShader combines multiple GLSL shaders into a program used for drawing.\n"
"   It must contain a vertex and fragment shaders, with an optional geometry shader.\n"
"\n"
"   The GLSL #version directive is automatically included at the top of shaders, and set to 330.\n"
"   Some preprocessor directives are automatically added according to the Operating System or availability:\n"
"   ``GPU_ATI``, ``GPU_NVIDIA`` and ``GPU_INTEL``.\n"
"\n"
"   The following extensions are enabled by default if supported by the GPU:\n"
"   ``GL_ARB_texture_gather`` and ``GL_ARB_texture_query_lod``.\n"
"\n"
"   To debug shaders, use the --debug-gpu-shaders command line option"
"   to see full GLSL shader compilation and linking errors.\n"
"\n"
"   :param vertexcode: Vertex shader code.\n"
"   :type vertexcode: str\n"
"   :param fragcode: Fragment shader code.\n"
"   :type value: str\n"
"   :param geocode: Geometry shader code.\n"
"   :type value: str\n"
"   :param libcode: Code with functions and presets to be shared between shaders.\n"
"   :type value: str\n"
"   :param defines: Preprocessor directives.\n"
"   :type value: str\n"
);
PyTypeObject BPyGPUShader_Type = {
	PyVarObject_HEAD_INIT(NULL, 0)
	.tp_name = "GPUShader",
	.tp_basicsize = sizeof(BPyGPUShader),
	.tp_dealloc = (destructor)bpygpu_shader_dealloc,
	.tp_flags = Py_TPFLAGS_DEFAULT,
	.tp_doc = bpygpu_shader_doc,
	.tp_methods = bpygpu_shader_methods,
	.tp_getset = bpygpu_shader_getseters,
	.tp_new = bpygpu_shader_new,
};

/** \} */


/* -------------------------------------------------------------------- */

/** \name gpu.shader Module API
 * \{ */

PyDoc_STRVAR(bpygpu_shader_unbind_doc,
".. function:: unbind()\n"
"\n"
"   Unbind the bound shader object.\n"
);
static PyObject *bpygpu_shader_unbind(BPyGPUShader *UNUSED(self))
{
	GPU_shader_unbind();
	Py_RETURN_NONE;
}

PyDoc_STRVAR(bpygpu_shader_from_builtin_doc,
".. function:: from_builtin(shader_name)\n"
"\n"
"   Shaders that are embedded in the blender internal code.\n"
"   They all read the uniform 'mat4 ModelViewProjectionMatrix', which can be edited by the 'gpu.matrix' module.\n"
"   For more details, you can check the shader code with the function 'gpu.shader.code_from_builtin';\n"
"\n"
"   :param shader_name: One of these builtin shader names: {\n"
"       '2D_UNIFORM_COLOR',\n"
"       '2D_FLAT_COLOR',\n"
"       '2D_SMOOTH_COLOR',\n"
"       '2D_IMAGE',\n"
"       '3D_UNIFORM_COLOR',\n"
"       '3D_FLAT_COLOR',\n"
"       '3D_SMOOTH_COLOR'}\n"
"   :type shader_name: str\n"
"   :return: Shader object corresponding to the given name.\n"
"   :rtype: :class:`bpy.types.GPUShader`\n"
);
static PyObject *bpygpu_shader_from_builtin(PyObject *UNUSED(self), PyObject *arg)
{
	BPYGPU_IS_INIT_OR_ERROR_OBJ;

	GPUBuiltinShader shader_id;

	if (!bpygpu_ParseBultinShaderEnum(arg, &shader_id)) {
		return NULL;
	}

	GPUShader *shader = GPU_shader_get_builtin_shader(shader_id);

	return BPyGPUShader_CreatePyObject(shader, true);
}

PyDoc_STRVAR(bpygpu_shader_code_from_builtin_doc,
".. function:: code_from_builtin(shader_name)\n"
"\n"
"   Exposes the internal shader code for query.\n"
"\n"
"   :param shader_name: One of these builtin shader names: {\n"
"       '2D_UNIFORM_COLOR',\n"
"       '2D_FLAT_COLOR',\n"
"       '2D_SMOOTH_COLOR',\n"
"       '2D_IMAGE',\n"
"       '3D_UNIFORM_COLOR',\n"
"       '3D_FLAT_COLOR',\n"
"       '3D_SMOOTH_COLOR'}\n"
"   :type shader_name: str\n"
"   :return: Vertex, fragment and geometry shader codes.\n"
"   :rtype: dict\n"
);
static PyObject *bpygpu_shader_code_from_builtin(BPyGPUShader *UNUSED(self), PyObject *arg)
{
	GPUBuiltinShader shader_id;

	const char *vert;
	const char *frag;
	const char *geom;
	const char *defines;

	PyObject *item, *r_dict;

	if (!bpygpu_ParseBultinShaderEnum(arg, &shader_id)) {
		return NULL;
	}

	GPU_shader_get_builtin_shader_code(
	        shader_id, &vert, &frag, &geom, &defines);

	r_dict = PyDict_New();

	PyDict_SetItemString(r_dict, "vertex_shader", item = PyUnicode_FromString(vert));
	Py_DECREF(item);

	PyDict_SetItemString(r_dict, "fragment_shader", item = PyUnicode_FromString(frag));
	Py_DECREF(item);

	if (geom) {
		PyDict_SetItemString(r_dict, "geometry_shader", item = PyUnicode_FromString(geom));
		Py_DECREF(item);
	}
	if (defines) {
		PyDict_SetItemString(r_dict, "defines", item = PyUnicode_FromString(defines));
		Py_DECREF(item);
	}
	return r_dict;
}

static struct PyMethodDef bpygpu_shader_module_methods[] = {
	{"unbind",
	 (PyCFunction)bpygpu_shader_unbind,
	 METH_NOARGS, bpygpu_shader_unbind_doc},
	{"from_builtin",
	 (PyCFunction)bpygpu_shader_from_builtin,
	 METH_O, bpygpu_shader_from_builtin_doc},
	{"code_from_builtin",
	 (PyCFunction)bpygpu_shader_code_from_builtin,
	 METH_O, bpygpu_shader_code_from_builtin_doc},
	{NULL, NULL, 0, NULL}
};

PyDoc_STRVAR(bpygpu_shader_module_doc,
"This module provides access to GPUShader internal functions."
);
static PyModuleDef BPyGPU_shader_module_def = {
	PyModuleDef_HEAD_INIT,
	.m_name = "gpu.shader",
	.m_doc = bpygpu_shader_module_doc,
	.m_methods = bpygpu_shader_module_methods,
};

/** \} */


/* -------------------------------------------------------------------- */

/** \name Public API
 * \{ */

PyObject *BPyGPUShader_CreatePyObject(GPUShader *shader, bool is_builtin)
{
	BPyGPUShader *self;

	self = PyObject_New(BPyGPUShader, &BPyGPUShader_Type);
	self->shader = shader;
	self->is_builtin = is_builtin;

	return (PyObject *)self;
}

PyObject *BPyInit_gpu_shader(void)
{
	PyObject *submodule;

	submodule = PyModule_Create(&BPyGPU_shader_module_def);

	return submodule;
}

/** \} */
